Man alone is able to convey precise information to his fellows through speech. ... The difference between human and animal language is, therefore, that whereas an animal can show by voice, gestures, or other sign that it is in a certain emotional or physical state, man is able to express such feelings in precise terms, and to indicate not only that he is hungry, but what he wishes to eat, not only that he is afraid but of what he is afraid.
――英文和訳演習 中級篇 伊藤和夫 駿台文庫